File this under "sad but true": The first signs of aging — sun spots, crow's-feet — show up earlier than we ever realized. In happier news, the right treatments can make all the difference.

We wouldn't mind reliving our first kiss or the first time we sprang for a pair of Louboutin stilettos. But spotting that first wrinkle is about as poignant a life moment as paying taxes for the first time — and it may happen just a few years after you mail in that debut 1040. Dermatologists report that signs of aging crop up as young as the mid-20s, and even the slightest change in the appearance of your skin may cause you to appear older. A recent study in the Journal of the American Academy of Dermatology found that uneven skin tone (sun spots, redness), in fact, drives the perception of age even more powerfully than wrinkles.

The main cause of most early signs of aging is the sun, which breaks down skin's supportive collagen and elastin fibers. " Photoaging, which is the damage to skin caused by sunlight, accounts for approximately 80 percent of wrinkles," says Tina Alster, clinical professor of dermatology at Georgetown University. "That's why monks who live their lives in dark monasteries have skin like a teenager when they're 80." Other evil forces include environmental pollutants, poor diet, lack of sleep, and stress — sins even monks can't always avoid.

The good news is, we can be saviors to our skin and ward off more wreckage, starting with wearing a broad-spectrum SPF 30 sunscreen every day. And those regretful errors of the past can be considerably reduced — without needles, lasers, or scalpels. "A topical product with the right ingredients can make a significant difference in the early stages of aging," says Alster. Here's how to get started:

Crow's feet
The cause:Laughter is apparently not the best medicine for the skin around the eyes —repeated muscle movement from smiling, laughing, and squinting creases the skin. It's probably no coincidence that a 2006 Aveeno study found that 84 percent of women notice the first signs of aging around their eyes. Part of the problem is people frequently skip sunscreen here because they're afraid it will irritate their eyes. Another culprit: "The skin around the eyes is the thinnest on the body," says David E. Bank, an associate in clinical dermatology at Columbia University/Presbyterian Hospital in New York City. "There isn't as much collagen and elastin there to begin with, which means once you start acquiring some sun damage, it's one of the first areas on the face to wrinkle."

The treatment: Smile — there's no need to become an expressionless robot and stop watching “30 Rock.” Instead, use an eye cream that contains one of the three ingredients dermatologists recommend to prevent and repair fine lines: retinoids, which stimulate cell turnover, increase collagen production, and are available as retinol in over-the-counter products (we like RoC Retinol Correcxion Eye Cream, applied at night), or in higher dose prescription creams such as Retin-A and Renova; peptides, which are protein fragments that help to boost collagen production (try Dr. Brandt r3p Eye Cream, day and night); and antioxidants, which neutralize the free radicals that break down skin cells and cause wrinkles (try Priori Radiance Eye Serum, with CoffeeBerry, every morning). "The better antioxidants can also make skin less sensitive to the sun," says Alster. Some of the most potent ones are green tea, CoffeeBerry, grape-seed extract, and soy.

For an immediate (albeit temporary) boost, a rich eye cream with humectants such as glycerin and hyaluronic acid will draw water to the skin, making crow's-feet harder to spot. (Try Clinique All About Eyes.) If your eye cream doesn't contain sun protection, apply a sunscreen designed not to irritate the eye area underneath it every day, such as Clarins Sun Eye Contour Care Ultra Protection SPF 30, and toss on a pair of UV-blocking shades to shield you from the sun and squinting.

Dark circlesThe cause: Dark undereye circles may have nothing to do with your sleeping habits. In fact, one trigger could be allergies. "They cause inflammation around the sinuses and dilated blood vessels under the eyes," says Alster. The simple solution — try an over-the-counter antihistamine such as Claritin. However, there are other, more stubborn demons at work here. "Directly beneath the surface of the thin undereye skin, you've got a multitude of tiny veins stacked on top of one another in crisscrossing directions. It's this confluence of color right beneath the skin that can give it the darkish hue." Other catalysts are leakage of iron oxide, called hemosiderin, from the capillaries, which appears as a brownish or bruiselike color (doctors are still scratching their heads as to why this happens, though sinus inflammation can set it off), and increased skin pigmentation caused by sun exposure.

The treatment: Dark circles are the common cold of dermatology — no one has figured out how to cure them. A cream won't do jack for dilated or leaky veins, and bleaching creams sound logical but don't make a memorable difference, says Amy Wechsler, assistant clinical professor in dermatology at SUNY Downstate Medical Center in New York City. However, an eye cream with peptides and retinoids, such as Jan Marini Age Intervention Eye Cream, helps to build up collagen and thicken the skin over time, making dark circles less apparent. Wechsler warns women not to rub their eyes, since that can lead to more dilated blood vessels.

Lines around the mouthThe cause: Sipping through a straw may seem daintier than chugging back a drink, but it can do a number on the skin surrounding your mouth over time. Pursing or puckering lips frequently — when sipping, smoking, or talking animatedly — is the prime source of fine lines around the mouth. The other is (you guessed it) sun damage. "The reason you see lines here early on is because the skin is exposed and it's a delicate area," says Alster. "Even if you diligently apply sunscreen to your face, it often gets rubbed off right near the mouth when you use a napkin or lick your lips."

The treatment: Doctors recommend sunscreen and skin creams with collagen-stimulating ingredients such as peptides and retinoids to help prevent lines from getting deeper and new ones from forming. (Try M Lab Anti-Aging Day Treatment SPF 15 or Peter Thomas Roth Uber Dry Sunscreen SPF 30.) "And for God's sake, quit smoking," says Bank. Wechsler tells patients to exfoliate around the mouth just as you do the rest of your face. "By regularly getting rid of the dead skin here, you reduce the appearance of lines," she says. For a temporary fix, a lotion containing hyaluronic acid, such as Shiseido Bio-Performance Advanced Super Revitalizer Cream, or glycerin, such as Kinerase Lotion, plumps up skin and makes lines less visible — or you could try one of the new products that fills in lines so they don't appear as deep. (They include Olay Regenerist Anti-Aging Lip Treatment and Revlon Age Defying Precise Wrinkle Eraser.) "However, ingredients that fill in the lines, such as collagen and silicone, can also pill on the skin, so apply just a thin layer," says Alster.

Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Dull skin
The cause: You may still be running marathons, but your skin cells are already losing steam by around age 30. "Cell turnover starts to slow down around this age, which leads to a buildup of dead skin, and it doesn't always slow at the same pace across your face," says Wechsler. "So you end up with patches of dead skin in some areas, causing your complexion to be dull, uneven, and rough."

The treatment: Exfoliate once a week to remove the top layer of dead cells and reveal the fresh skin underneath. Doctors prefer at-home alpha hydroxy acid (AHA) or salicylic acid peels over scrubs. "People tend to rub harshly in certain areas which can cause uneven exfoliation and irritation," says Alster. "A peel provides an even layer of product across the face to chemically loosen dead cells." Don't leave a peel on for longer than the instructions advise, and be sure to moisturize afterward. If you have sensitive skin, test the product first on a small patch of skin in front of your ear, says Wechsler. MD Formulations Daily Peel Pads (with salicylic acid) and Juice Beauty Green Apple Peel Sensitive Pads (with AHAs) make it easy to exfoliate in one quick swipe. To force your skin into the habit of faster cell turnover, introduce products containing ingredients that speed up the process into your regimen. Try a mild salicylic acid cleanser, such as Dermalogica Clearing Skin Wash, or a cream with either alpha hydroxy acid or retinol (we like Neutrogena Healthy Skin Face Lotion SPF 15 or Remergent Retinol Therapy) — just don't use the creams within an hour of the salicylic cleanser or the AHA peel to avoid irritating skin (by doubling up on AHAs) or negating the effects (salicylic acid and AHAs can lessen the effectiveness of retinol).

Hyper-pigmentation
The cause: Hyperpigmentation is the clinical term for brown spots, freckles, and dark patches — all caused by an overproduction of melanin. Sun damage is typically to blame for small, individual brown spots, while a rise in estrogen levels in your body — often brought on by pregnancy or certain types of birth control pills — causes larger, irregular splotches of dark skin known as melasma.

The treatment: The only over-the-counter ingredient strong enough to actually bleach skin is hydroquinone — "It can get rid of a dark spot or melasma entirely," says Wechsler. There has been controversy over the ingredient because of some patients who used it in extremely high concentrations and developed darker spots, but as of now, "it remains the best treatment for hyperpigmentation," says Wechsler. (You can find it over the counter in Murad Age Spot & Pigment Lightening Gel.) In addition, because AHAs and retinol help speed up cell turnover, they prompt skin to shed the darker cells while also evening out melanin production so you don't get clusters of pigment. (Try Dr. Michelle Copeland AHA Face Cream or L'Oréal Advanced Revitalift Night Cream.)

It takes four to eight weeks for a lightening agent to completely fade a dark area of skin, and brown spots and melasma are notorious for recurring. "Patients will tell me that the bleaching creams don't work, and then I'll find out they're not wearing sunscreen," says Fredric Brandt, a cosmetic dermatologist in New York City and Miami. "Unless you apply a broad-spectrum sunscreen every day and avoid prolonged sun exposure, the treatments aren't going to work."

Dryness
The cause: Oil is in overdrive when you're a teenager, then it nearly runs dry as you get older. "Your skin gets about 10 percent drier every decade," says Bank. While oil production decreases, the lipid barrier of skin, which traps and holds in moisture, becomes increasingly defective over time. "You've got a double whammy of less moisture production and less ability to hold moisture in the skin," says Bank.

The treatment: You need a good moisturizer, but a thick, rich cream could clog your pores when you're young. "Your moisturizer should sink in quickly but leave skin feeling supple," says Bank. Try a lightweight moisturizer with ceramides (which help build up the lipid barrier), such as Elizabeth Arden Ceramide Plump PerfectMoisture Cream SPF 30 or CeraVe Moisturizing Lotion. If your skin still feels dry, begin next time with a hydrating serum such as Vichy Aqualia Thermal Serum or Bioelements x10, then apply your moisturizer. If your skin feels tight after you wash it, "that means you've stripped it of all its natural, protective oils," says Wechsler. Switch to a cream cleanser — try Lancome Glatee Comfort. And be sure to exfoliate weekly with a chemical peel (it's gentler on dry skin than a scrub) — clearing away dead cells helps your moisturizer penetrate better. (Try Avon Anew Clinical Advanced Retexturizing Peel.)

Weathered neck and décolletageThe cause: Call it the forgotten territory. Even those who diligently apply sunscreen to their face often forget their neck and chest — and because the skin there is thinner and has fewer oil glands than the face, it's particularly susceptible to early signs of aging such as horizontal neck lines and brown chest spots. And once again, blame it on the sun.

The treatment: The same ingredients you use to treat lines and dark spots on your face will work on your neck and chest — but because the skin here is thin, it's more sensitive. To minimize irritation, apply your face cream to your neck and chest just two or three times a week. If you're particularly sensitive, use a neck cream — it typically has a lower concentration of active ingredients, such as retinols and lightening agents, than face creams. (We like Cellex-C Advanced C Neck Firming Cream.) And we may sound like a broken record here, but a broad-spectrum sunscreen applied daily to this area — even in the wintertime — is your best defense against further damage.